Patterns of Fish Assemblage, Growth, and Diet Composition in a Tropical River between Two Cascading Hydropower Dams

Construction of cascade dams has been shown to have impacts on fish assemblages and biodiversity. Yet, there is no literature in the Murum River that connects cascading Bakun Sarawak, Malaysia. Hence, study this modified ecosystem necessitated better understand effects dam construction fauna. For this, samples were caught at five stations located along river during both dry wet seasons. Environmental parameters taken concurrently with sampling. Length-weight relationship, condition factors, diet composition selected species also determined. The present demonstrated are indications impact formation a complex River, is, changing from shallow downstream Dam deep transitional inundated zone reservoir. exhibited lowest diversity, richness, evenness season due low pH DO coupled high turbidity. biological indices improved when water quality season. On contrary, diversity tributary station decreased remarkably season, likely migration onset rainy This showed Barbonymus schwanenfeldii wider feeding habit which contributes its higher distribution abundance River. growth patterns B. schwanenfeldii, Cyclocheilichthys apogon, Hampala macrolepidota, Lobocheilos ovalis, Osteochilus enneaporos than Overall, factor all native was poor fair condition, whereas exotic species, Oreochromis mossambicus, excellent (K value > 2) for increase number O. mossambicus indicates intrusion potential threat Continuous monitoring essential detect in-time risk issues associated environmental degradation invasion regulated ecosystem.